Solute segregation during modified vertical gradient freezing of alloyed compound semiconductor crystals with magnetic and electric fields

Single crystals of gallium-aluminum-antimonide are solidified from a solution of molten gallium-antimonide and aluminum-antimonide. Electromagnetic stirring can be induced in the melt by applying a weak electric field together with a weak axial magnetic field. This paper presents a numerical model which uses a Chebyshev spectral collocation method with a second-order implicit time integration scheme with Gauss-Lobatto collocation points. This investigation models the unsteady motion and solute transport during vertical gradient freezing by submerged heater growth with electromagnetic stirring. The radial homogeneity in the crystal improves as the solute's concentration increases. (c) 2006 Elsevier Ltd. All rights reserved.